.drag-box {
    width: 100px;
    height: 100px;
    background-color: #ccc;
    cursor: move;
}

.drop-box {
    width: 310px; /* 网格单元大小为 100px，加上网格线的宽度 */
    height: 310px;
    background-color: #f1f1f1;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 2px; /* 网格线的宽度 */
}

.grid-cell {
    background-color: white;
}
